A sign painter paints individual numerals for a row of 50 houses. The houses are numbered with consecutive integers from 1 to 50. How many 9s are painted?
Answer: For every ten consecutive integers 1-10, 11-20, and so on until 50, there is one 9 painted. Since there are 5 sets of ten consecutive integers, there are $\boxed{5}$ nines painted.